The present invention relates to a laser marking apparatus with the emission of laser beam(s) or ray(s) (hereinafter, laser beam) to an objective, and particularly to a laser line beam emitting apparatus, which is directed to a laser marking instrument for the construction industry for measurement of objectives such as walls, ceilings, floor, and etc. of a building under construction, with the emitted beams.
Nowadays, the construction industry uses the laser line emitting apparatus in place of the marking (or ink pad) technique, which carpenters or construction workers measure the objectives by drawing a vertical or horizontal line on respective surfaces with a Chinese ink or chalk.
The apparatus produces a laser line beam (a drawn line) by collimating diffusive semiconductor laser beam through a collimator lens therein, and then generating unidirectional diffusion of the collimated laser beam through a cylinder-shaped rod lens therein. In addition, it performs the horizontal or vertical preservation (a plumb or horizontal line) of the laser line beam by the gimbals mechanism. The gimbals mechanism allows for constantly positioning of a laser beam source unit having united hold of the semiconductor laser, and collimator and rod lenses through its holder. In the gimbals mechanism, its pendulum maintains the constant position of the laser beam source unit disposed therein such that even though the laser line beam emitting apparatus inclines downward or upward, it provides the horizontal or plumb laser line beam.
The construction industry desires possibility of a produced straight line, which is drawn without disconnection to the wide angle that is within an area extending from, for example, one wall to a ceiling, the other wall, and floor, or a produced horizontal line, which is drawn to the wide angle that it is within an area extending between surrounding three or four walls, in the building under construction. FIGS. 9 or 10 shows examples of the laser line beam emitting apparatus as designed or proposed in accordance with the desire.
FIG. 9 shows, as a conventional example, a laser line emitting beam apparatus with a pair of laser source units 1 and 2. The laser source units 1 and 2 have collimator lenses 12 and 22, and rod lenses 13 and 23, which are held by their holders, respectively. The paired laser source units 1 and 2 are disposed such that respective optical axes have a horizontal arrangement with respective proximal ends opposing to each other. Each of the rod lenses 13 and 23 is disposed perpendicularly with respect to the horizontal optical axis. Thus, the laser beam from respective laser source units 1 and 2 widthwise spreads to each rightward and leftward 90 degrees (360 degrees around the whole apparatus) so that the apparatus provides drawing of a straight horizontal line drawn between objectives ahead of, behind, and opposite sides thereof. It is obvious that rotation through 90 degrees of the laser source units 1 and 2 also allows a drawn vertical line with respect to the horizontal, the vertical line extending between objectives above, below, and opposite sides of the horizontal apparatus.
FIG. 10 shows, as another conventional example, a laser line beam emitting apparatus having a laser beam source unit 3 with a semiconductor laser 31 and a collimator lens 32, and a conical mirror 34. According to the apparatus, the direction of the laser beam emitted from the semiconductor laser 31 is from down to up. The emitted laser beam from the semiconductor laser 31, which becomes parallel flux through the collimator lens, goes toward the conical mirror such that the centered flux reaches the vertex of the conical mirror 34. Hence, the laser flux is reflected from the reflective conical mirror face in the radial direction to 360 degrees angle area. In FIG. 10, it is obvious that the vertically directing of the central axes of the conical mirror 34 allows for drawing of a horizontal line on the objectives, while the horizontally directing of the central axes of the conical mirror 34 (the direction of the laser beam is sideward) allows for drawing of a vertical line on objectives.
The conventional apparatus as shown in FIG. 9 has a problem of that it is expensive because of its requirement of installations of its two laser beam source units. In addition, it requires individual adjustments of angles and further positions of rod lenses of respective laser beam source unit, for provision of a straight line, which will be drawn on objectives therearound. Such the complex adjustment also has a problem of that it adds the expensive cost to the apparatus.
Furthermore, the conventional apparatus as shown in FIG. 10 also has a problem of which it is expensive because of that high precise production of the conical mirror is difficult and the conical mirror requires reflective material being deposited on the conical surface. In addition, the adjustment of coaxial position of the laser flux center and, conical mirror vertex has great difficulty.
The present invention provides solution to the foregoing problem of the prior arts. The present invention is directed to provide a method for emitting a precise laser line beam and an apparatus thereof, which is directed to a laser marking instrument which allows for precisely drawing of a horizontal or vertical line to the wide angle area therefrom just to 360 degrees, in spite of a simplified structure thereof as well as reduction in the parts and easier adjustment thereof.
The present invention provides a laser line beam emitting apparatus, which uses a single laser beam source unit. This contributes to decrease in the number of the parts. The laser beam source unit according to the present invention comprises a laser beam source, a collimator lens, and a cylindrical rod lens. The cylindrical rod lens comprises a complete transparent area, and a semitransparent area in part provided thereon as opposed to a laser beam emitted from the laser beam source.
The semitransparent area of the rod lens has the reflection and diffusion of the collimated, emitted laser beam in a first direction, while the complete transparent area has the refraction and diffusion of the rest beam passing thorough the semitransparent area in a second direction.
The desired location of the semitransparent area is at 140 or less degrees angle with respect to the center axis of the rod lens. Because the semitransparent area at over 140 degrees angle causes diffusion of the laser beam by 280 degrees angle with respect to the center axis of the rod lens. Accordingly, this causes overlapping problem of the reflected and refracted beams.
The rod lens may be arranged to vertically or horizontally cross the optical axis of the collimated, emitted laser beam. The vertical arrangement of the rod lens with respect to the optical axis provides emission of the laser line beam to objective ahead of, behind, and opposite sides of the laser line beam emitting apparatus, while the horizontal arrangement of the rod lens with respect to the optical axis provides emission of the laser line beam to objective above, below, and opposite sides of (or ahead of, and behind) the laser beam emitting apparatus.
The laser line beam source unit further comprises a holder for hold of the laser beam source, the collimator lens, and the rod lens. The laser beam source is attached at the trailing end of the holder, and the holder has a cylindrical mirror attached at the approximate medium portion on the side of the leading end thereof. The collimator lens is disposed in the interior cylindrical mirror, and the rod lens is attached at the distal end of the cylindrical mirror.
The cylindrical mirror for lens and the holder of the laser line beam source unit have pairs of opposite slits through which the diffused laser beam from the rod lens may passes, respectively.
The location of the rod lens with respect to the laser line beam is easier than the prior arts. The cylindrical mirror shows disposition relationship between the rod lens and the laser beam for adjustment of location therebetween. In addition, the pairs of slits of the cylindrical mirror for lens and the holder also provide a performance of correct location of the cylindrical mirror to the holder.
In the laser line beam emitting apparatus according to the present invention, the laser line beam source unit is assembled into a pendulum, which is hung from a gimbals mechanism. The pendulum provides possible swing of the laser line beam source unit between the front and the back, and the right and the left.
The gimbals mechanism comprises respective four shafts and three links linked in series through the four shafts. The four shafts comprises the first pair of shafts horizontally extending from a housing surface of the laser line beam emitting apparatus, and the pair of second shafts which is at right angles to the first paired shafts. The first link has free swings about the first shaft on the side of the trailing end thereof, and linkage to the second link through the second shaft on the side of the leading end thereof. The second link has free swings about the second shaft on the side of the trailing end thereof and the leading end of the first link, and linkage to the third link thorough the third shaft on the side of the leading end thereof. The third link has free swings about the third shaft on the side of the trailing end thereof, and linkage to the pendulum through the fourth shaft on the side of the leading end thereof. Hence, the pendulum may freely swing.
The pendulum may have a conductive plate attached to its lower portion. The conductive plate laterally extends from the lower pendulum portion. The extending conductive plate is sandwiched between a pair of magnets, which are fixed on inner surfaces of respective horizontal plates of an inverted C shape yoke. Each of the magnets is spaced apart from the conductive plate. The conductive plate, inverted C shape yoke, and pairs of magnets together makes up the construction of a brake device for pendulum. Movements of the conductive plate through the swinging pendulum causes generation of eddycurrent between the conductive plate and the pair of magnets to brake the pendulum.
Thus, the single laser beam source unit according to the present invention allows for reduction in cost of the laser line beam emitting apparatus. The laser beam source, collimator lens, and rod lens, which are assembled into the pendulum through the laser beam source unit, provides the constructional simplicity. The single laser beam source unit provides easy formation of a straight line horizontally or vertically surrounding the laser line beam emitting apparatus or passing objectives ahead, behind, and opposite sides, or above, below, and opposite sides (or ahead or behind) thereof. The cylindrical mirror provides easy adjustment in location of the rod lens with respect to the laser beam. In addition, the conductive plate at the lower portion of the pendulum, the inverted C-shape yoke, and the pairs of magnets on respective horizontal plates of the yoke make up the construction of a brake device that it brakes the pendulum swinging.